高稳定性光散射法颗粒物浓度传感器

High Stable Light Scattering Based Particulate Matter Concentration Sensors

我国针对环境空气颗粒物污染治理的政策日益严格。为解决工业现场长期测量稳定性的问题,国内外研究者提出采用鞘流结构来制约颗粒物重叠和光腔污染的方案。从光腔结构、质量浓度计算方法和气路结构三方面入手,对传感器的测量精度和抗污染性进行优化。基于光学追迹,对光腔结构进行模拟,以实现散射光的最佳收集效果;通过修正特征参数,降低传感器的测量误差;设计简易内循环模式的鞘气保护结构,降低由颗粒重叠导致的测量误差并对光腔进行保护;研究上述结构下气体流速对总尘浓度(TSP)、PM_(10)和PM_(2.5)检测结果的影响,设置最优的气泵流量。实验结果表明,得到了高稳定性的气溶胶浓度传感器,可同时测量TSP、PM_(10)和PM_(2.5)的质量浓度,测量误差小于±5%。

The policy for controlling air particulate matter pollution is becoming increasingly stringent.To address the issue of measurement stability,researchers proposed the sheath flow structure used to limit particle overlap and the pollution of light cavity.To achieve high stability concentration measurement,this paper optimizes the measurement accuracy and antipollution performance of the sensor from three perspectives:optical cavity structure,mass concentration calculation method,and gas path structure.The optical cavity structure is simulated using optical tracing to achieve the best-scattered light collection effect.Modifying the sensor's characteristic parameters reduces its measurement error.The simple sheath gas protection structure with internal circulation mode is designed to reduce measurement error caused by particle overlap and protect the optical cavity.The effect of gas flow rate on the detection results of total dust concentration(TSP),PM_(10),and PM_(2.5) is studied,and the optimal air pump flow rate is set.The experimental results show that the aerosol concentration sensor simultaneously achieves a high stable mass concentration measurement of TSP,PM_(10),and PM_(2.5),and the measurement error is<±5%.